src/dirname.c

   1 /* dirname -- strip suffix from file name
   2
   3    Copyright (C) 1990-2023 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 /* Written by David MacKenzie and Jim Meyering. */
  19
  20 #include <config.h>
  21 #include <getopt.h>
  22 #include <stdio.h>
  23 #include <sys/types.h>
  24
  25 #include "system.h"
  26 #include "error.h"
  27
  28 /* The official name of this program (e.g., no 'g' prefix).  */
  29 #define PROGRAM_NAME "dirname"
  30
  31 #define AUTHORS \
  32   proper_name ("David MacKenzie"), \
  33   proper_name ("Jim Meyering")
  34
  35 static struct option const longopts[] =
  36 {
  37   {"zero", no_argument, NULL, 'z'},
  38   {GETOPT_HELP_OPTION_DECL},
  39   {GETOPT_VERSION_OPTION_DECL},
  40   {NULL, 0, NULL, 0}
  41 };
  42
  43 void
  44 usage (int status)
  45 {
  46   if (status != EXIT_SUCCESS)
  47     emit_try_help ();
  48   else
  49     {
  50       printf (_("\
  51 Usage: %s [OPTION] NAME...\n\
  52 "),
  53               program_name);
  54       fputs (_("\
  55 Output each NAME with its last non-slash component and trailing slashes\n\
  56 removed; if NAME contains no /'s, output '.' (meaning the current directory).\n\
  57 \n\
  58 "), stdout);
  59       fputs (_("\
  60   -z, --zero     end each output line with NUL, not newline\n\
  61 "), stdout);
  62       fputs (HELP_OPTION_DESCRIPTION, stdout);
  63       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  64       printf (_("\
  65 \n\
  66 Examples:\n\
  67   %s /usr/bin/          -> \"/usr\"\n\
  68   %s dir1/str dir2/str  -> \"dir1\" followed by \"dir2\"\n\
  69   %s stdio.h            -> \".\"\n\
  70 "),
  71               program_name, program_name, program_name);
  72       emit_ancillary_info (PROGRAM_NAME);
  73     }
  74   exit (status);
  75 }
  76
  77 int
  78 main (int argc, char **argv)
  79 {
  80   static char const dot = '.';
  81   bool use_nuls = false;
  82   char const *result;
  83   size_t len;
  84
  85   initialize_main (&argc, &argv);
  86   set_program_name (argv[0]);
  87   setlocale (LC_ALL, "");
  88   bindtextdomain (PACKAGE, LOCALEDIR);
  89   textdomain (PACKAGE);
  90
  91   atexit (close_stdout);
  92
  93   while (true)
  94     {
  95       int c = getopt_long (argc, argv, "z", longopts, NULL);
  96
  97       if (c == -1)
  98         break;
  99
 100       switch (c)
 101         {
 102         case 'z':
 103           use_nuls = true;
 104           break;
 105
 106         case_GETOPT_HELP_CHAR;
 107         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 108
 109         default:
 110           usage (EXIT_FAILURE);
 111         }
 112     }
 113
 114   if (argc < optind + 1)
 115     {
 116       error (0, 0, _("missing operand"));
 117       usage (EXIT_FAILURE);
 118     }
 119
 120   for (; optind < argc; optind++)
 121     {
 122       result = argv[optind];
 123       len = dir_len (result);
 124
 125       if (! len)
 126         {
 127           result = &dot;
 128           len = 1;
 129         }
 130
 131       fwrite (result, 1, len, stdout);
 132       putchar (use_nuls ? '\0' :'\n');
 133     }
 134
 135   return EXIT_SUCCESS;
 136 }